Integration, lateralization, and animal experience

Abstract

Many vertebrate animals approximate, to various degrees, the “split‐brain” condition that results from surgery done in humans to treat severe epilepsy, with very limited connection between the left and right sides of the upper parts of the brain. The split‐brain condition has been the topic of extensive philosophical discussion, because it appears, in some circumstances, to give rise to two minds within one body. Is the same true of these animals? This article attempts to make progress on two difficult topics—animal experience, and the consequences of the human split‐brain condition—by considering both at once.

The Case for Octopus Consciousness: Unity

“…Despite a large neural allocation to managing the sensory-motor coordination of the arms, the octopus appears to centre learning and cognition in the brain and though the study of intersensory integration has just begun, it is promising in unravelling the integration of incoming information. Nevertheless, we are not going to find out where in a sophisticated and multifaceted brain the seat of cognition and consciousness is 'parked', and we should move away from the idea, as Godfrey-Smith [33] suggests, that "experience is always housed neatly" and look for a sophisticated organization of 'self' that lives up to the complexity of the nervous system that fosters it.…”

“…Looking at the data on people with split brains, de Haan et al [22] pointed out that perception appears to be lateralized while actions are bilateral. Discussing what these studies tell us, Godfrey-Smith [33] pointed out that a person or animal is a coherent unified agent, presumably with consciousness. As an agent, it has a point of view (also see [34]).…”

Modelling developments in consciousness within a multidimensional framework

“…The question of whether non-human animals such as birds and octopuses can house more than one consciousness has also been raised ( Godfrey‐Smith 2021 ). Carls-Diamante (2022) has attempted to advance the view that each of an octopus’s arms has its own consciousness.…”

Where Is It Like to Be an Octopus?

“…Importantly, they are capacities of the intact octopus, i.e., they emerge as the result of the complex interaction between the components of the nervous system. Consequently, investigations into consciousness in octopuses are based on a construal of the animal as a coherent agent ( Godfrey-Smith, 2020 ), whose complex behaviour is the outcome of profound embodiment ( Hochner, 2013 ) that evolved as a unique solution to the challenge of controlling a flexible body with immense sensory processing demands. Now, although we are unlikely to ever have complete knowledge about what it is like to be an octopus, attempting to understand consciousness in such creatures requires that we take a closer view at its arm nervous system, whose participation in cognition and behaviour is vital and indispensable.…”

“…In the same vein, Peter Godfrey-Smith writes that minds (understood as equivalent to a conscious field) “have what we might call characteristic interfaces …that connect them with external objects and conditions. Sensing and action are the interfaces, and these mark the boundaries of a mind” ( Godfrey-Smith, 2020 , p. 290). Consequently, demarcating a unit that potentially generates a conscious field involves identifying constituent substrates that are responsible for sensation and action.…”